Abstract. Enterprise Architecture (EA) is managed, developed, and maintained by Enterprise Architecture Implementation Methodology (EAIM). There is ineffectiveness in existing EAIMs due to the complexities; these complexities come from EAIM's processes, models, methods, and strategy. Consequently, EA projects may be faced with lack of support in the following parts of EA: requirement analysis, governance and evaluation, a guideline for implementation, and continual improvement of EA implementation. This research aims to represent an Agent-Oriented based EAIM. The proposed EAIM was evaluated by means of a case study. The results show that proposed EAIM could directly affect the effectiveness of EA implementation in following items: reducing the mismatch between business and IT, defining reachable goals for enterprise, employing easy implementation practices and easy learning procedure, using efficient documentation, applying appropriate communication among project team member, providing an effective environment for alignment of business and IT, and using effective plan for governance and migration plan. This research extends the application of Agent Technology, which provides new area of research for academics and provides effective EAIM, which can be employed by practitioners in EA project.